<!DOCTYPE html>
<html lang="">

<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width,initial-scale=1.0">
  <link rel="icon" href="">
  <title>商品管理系统</title>
</head>

<body>
  <div id="app"></div>
</body>
<style>
  #app {
    height: 100vh;
    width: 100vw;
  };
  *{
    margin: 0;
    padding: 0;
  }
</style>
</html>